"We didn't tackle great," O'Brien said. "We have to do a better job coaching. Any time you lose, it's a team loss, everybody's in it together.
"I felt pretty good the way we were playing coming in. But it's a team loss. We made mistakes on both sides of the ball. We'll try to watch the film tomorrow and look at all those things. It's a team loss. Both sides of the ball need to improve, special teams needs to improve."
Penn State gained 455 yards on offense and got big games from junior Zach Zwinak with 128 yards in 21 carries and three touchdowns, and from junior Allen Robinson, who caught nine passes for 143 yards and one touchdown. The Nittany Lions dug their way out of a 28-10 third-quarter hole to get the deficit down to seven, 31-24, early in the fourth quarter on Zwinak's third touchdown.
However, after a UCF field goal, Zwinak fumbled the ball at the Knights 29 for Penn State's only turnover of the night.
"We were rolling pretty good there," O'Brien said, "and we just can't do those things."
But the Lions got a reprieve when a long snap sailed over the head of the UCF punter, putting Penn State in business at the visitors' 25. Christian Hackenberg's 5-yard touchdown pass to Robinson made it a three-point game.
With only one timeout remaining, O'Brien decided to pass on an onside kick and try to kick the ball over the head of the UCF return man while keeping the ball out of the end zone, but Sam Ficken's kick just trickled in. Central Florida got a key first down and ran out the clock.
Bortles completed 20 of 27 passes for 288 yards. His third touchdown pass of the game, a 25-yarder to Josh Reese, gave the Knights a 28-10 lead midway through the third quarter.
"UCF is a great team," said safety Malcolm Willis, who accounted for Penn State's only takeaway with a second-quarter interception. "They have a lot of good playmakers on the offensive side of the ball. They made the majority of the plays tonight. We have to buckle down for next week."
Or as defensive tackle DaQuan Jones said, "We didn't bring our A-game today."
O'Brien, however, said he knows his team will bounce back from Saturday night's disappointment.
"Nobody's going anywhere," he said. "We're just going to go back to the drawing board and figure out what we can do better and coach these guys better and get them to play better. We're with you, you're with us, through thick and thin. Everybody look in the mirror and see what we can do better tomorrow."
Contact Joe Juliano at firstname.lastname@example.org. Follow on Twitter @JoeJulesInq.